A New Locality of Well-Preserved Silicified Early Permian Brachiopods

Home , Chonetidina, Loei Province, Rugosochonetidae, Strophomenata

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A new locality of well-preserved siliciﬁ ed Early Permian brachiopods in Loei province, NE Thailand

Sakchai Juanngam1,2*, Mongkol Udchachon1,3 Received: 30 July 2013; Accepted: 15 October 2013

Abstract Several localities of brachiopod faunas have been reported in the Loei area found mostly in late Palaeozoic shales and limestones. Silicifi ed articulate brachiopods were observed in the Pha Dam section east of Loei, in the Nam Suay sub-district, Na duang district. This section is part of the Nam Mahoran Formation according to the geological map published by DMR. It consists of brown shales and siltstones interbedded with dark grey limestones and the brachiopod assemblage includes cf. Chonetinella, Rhipidomella, Phricodothyris, Marginifera, Reticulatia, STROPHOMENIDA fam. indet., and SPIRIFERIDA fam. indet.. These specimens are relatively small in size, silicifi ed and mostly consist of single-valves. The occurrence and characteristics of the brachiopods in this section differ from those reported by previous workers in the area. This locality also contains several other abundant and diverse invertebrate groups such as bryozoans, crinoids and solitary corals. The rocks from both sections consist of shale and limestone. The brachiopods, corals, bryozoans and crinoids are interpreted as having lived in shallow marine or shelf environments. Preliminary age determinations are based mainly on brachiopods and suggest that the rocks should be reassigned to the Lower Permian which is compatible with the age assigned in the geological map of Thailand. Keywords: silicifi ed brachiopods, invertebrate fossils, Loei province Introduction This paper contains preliminary descriptions and The Permian brachiopod faunas of Thailand are both age conclusions which will be refi ned in future studies. diverse and abundant and are found both on the Sibu- Specimens were collect by the writers in the dry seasons masu and Indochina Terranes. Thai brachiopods are of 2010 – 2012 in collaboration with the staff of the very important for tectonic, palaeoclimatic, stratigraphic Sirindhorn museum and Phuwiang Dinosaur museum, and palaeoenvironmental studies1. Thai Sibumasu bra- Department of Minerals Resources and Palaeontological chiopods have been reported in many monographs and Research and Education Centre, Mahasarakham Universi- papers2,3,4 but the Indochina faunas of Thailand have ty. The materials were collected in situ and an attempt was only been documented in a few relatively brief studies. made to collect all visible specimens, they was cleaned Yanagida, et al. in 19745, 19996 and Pérez-Huerta, et al. in Sirindhorn museum’s laboratory by pneumatic air pen. in 20077 have described a total of 59 species from 49 The brachiopods at this site are not highly - abundant genera. Thailand brachiopods have been described from and well preserved silicifi ed sample. The brachiopods at the following localities. this site are particularly abundant not particularly well preserved.

1 Department of Biology, Faculty of Science Mahasarakham University, Khamrieng, Kantharawichai, Mahasarakham, 44150, Thailand 2 Sirindhorn Museum, Department of Mineral Resources, Kalasin, Thailand 3 Palaeontological Research and Education Centre, Mahasarakham University, Khamrieng, Kantharawichai, Mahasarakham 44150, Thailand * Corresponding author: [email protected] 404 Juanngam et al. J Sci Technol MSU

Terminology and classifi cation 1.2 Diagnosis The terminology used here follows Williams and Rowell, See Cocks. and Jia-Yu, 200011 page 216 196510. The supraspecifi c classifi cations for taxa within the 1.3 Description order Strophomenida follow Cocks. and Jia-Yu, 200011. Small-size shells are about 2 cm. wide; sub- The supraspecifi c classifi cations for taxa within the order trigonal shell outline; the greatest width is at mid-length; Productida follow Brunton et al., 200012. The supraspecifi c weak sulcus; the surface ornamentation with strong plicae classifi cations for taxa within the order Orthida follow Wil- and sparse short spines. Internal structure cannot be liams and Harper, 200013. The supraspecifi c classifi cations observed. for taxa within the order Spiriferida follow Carter et al., 1.4 Measurement (mm.) 200614. Specimen Length Width Thickness SM2014-2-001 13.20 19.30 11.05 Geological setting SM2014-2-002 13.15 18.30 7.45 The Pha Dam section is located in the Na-Duang district, SM2014-2-003 12.20 19.05 9.50 Loei province. It is covered by marine sedimentary rock ranging up to the Upper Permian8,9. It is assigned to the Subphylum RHYNCHONELLIFORMEA Williams Nam Mahoran Formation of the Saraburi Group, which et al., 1996 consists predominantly of white to grey, thick-bedded 2. Chonetinella sp. limestone of algal reef origin, brownish shale, calcareous Order PRODUCTIDA Sarytcheva and Sokols- shale and in the lowest beds is reddish brown sandstone kaya, 1959 interbedded with chert. It outcrops in a North – South belt Suborder CHONETIDINA Muir – Wood, 1955 East of Muang district Loei province extending to the East Superfamily CHONETOIDEA Bronn, 1862 and Southeast of Wang Sa Phung district Loei province. Family RUGOSOCHONETIDAE Muir – Wood, 1962 The Pha Dam section is a road-cut section between a Subfamily RUGOSOCHONETINAE Muir – Wood, 1962 small hill in the east of Loei by highway number 3117 Genus Chonetinella Ramsbottom, 1952 (Figure 1), which contains folded brown siliceous shale Chonetinella sp. intercalated with dark grey limestone. Figure 3B 2.1 Examined specimen Systematic palaeontology Only one well preserved external pedicle Repository Studied specimens are housed in the Sirin valve. Registered specimen SM2014-2-004. dhorn Museum, Department of Mineral Resources, Kalasin, 2.2 Diagnosis Thailand with specimen numbers prefi xed herein SM. See Grant, 19762 page 74 and Brunton Phylum BRACHIOPODA Duméril, 1805 et al., 200012 page 405 Subphylum LINGULIFORMEA Williams et al., 1996 2.3 Description Class STROPHOMENATA Williams et al., 1996 Small-size shell is about 2 cm. wide; sub- 1. STROPHOMENIDA fam. Indet. trigonal shell outline; the greatest width is at mid-length; Order STROPHOMENIDA Öpik, 1934 weak sulcus; the surface ornamentation with strong plicae Figure 3 A and sparse of short spines. Internal structure cannot be 1.1 Examined specimen observed. Three poorly preserved external pedicle 2.4 Discussion valves. Registered specimens SM2014-2-001 to Chonetinella sp is always characterized by a SM2014-2-003 distinct sulcus and the bilobate character of lateral sides which originate near the umbo, remarkably ventral valve Vol 33. No 4, July-August 2014 A new locality of well-preserved silicifi ed Early Permian brachiopods in Loei province, 405 NE Thailand convex with deep median sulcus. Our Chonetinella sp. is 3.4 Discussion quite close to Chonetinella sp., Yanagida15 (1975, p. 20, Marginifera is characterized by its shell pl. 2, fi gs 8 – 9) from Huai Luang, Loei – described as outline, costation, and spines. Our specimens are similar to “sulcus distinct, originating near beak as a distinct groove, Marginifera arenaria Grant2 (1976, p109, pl.24, fi gs. 1 – 34) surface ornamented by fi ne radial capillae”; and it is also from Ko Muk, Trang from their spines and general outline are similar to Chonetinella cymatilis, Grant2 (1976, p77, and but it is quite different in ornamentation. While M. pl.16, fi gs. 1 – 58) from Ko Muk, Trang in general out- drastica Grant2 (1976, p110, pl.26, fi gs. 1 – 23) from Ko line, sulcus and ornamentation. They also look similar to Muk, Trang and Marginifera cf. drastica Thonnarat, et al.16 Chonetinella andamanensis, Waterhouse, et al.3 (1981, p. (2012, p. 45, pl. 7, fi gs. A – F) from Ban Ao Nam, Krabi, 65, pl. 2, fi gs. 18 – 19, pl. 3, fi gs. 1 – 18) from Ko Yao Noi, M. nesiotes Grant2 (1976, p112, pl.27, fi gs. 1 – 34), M. Krabi and Chonetinella cf. andamanensis,Waterhouse otaria Grant2 (1976, p115, pl.25, fi gs. 1 – 24) from Ko Thonnarat, et al.16 (2012, p. 41, pl. 4, fi gs. B – I) from Muk, Trang and Marginifera drastica Yanagida6 (1999, Ban Ao Nam, Krabi – bisected by deep sulcus, very nar- p.129, pl.29, fi gs 2, 3, 5 – 9) from Khao Hin Kling area row fl oor. near Petchaboon are different in having weak costae. 2.5 Measurement (mm.) The Huay Nam Suay specimens are closely similar to Specimen Length Width Thickness M. banphotensis using its external characters, Yanagida5 SM2014-2-004 10.85 19.90 2.65 (1964, p.11, pl.3, fi gs 2 - 3) from near Tambon Ban Phot of Petchaboon province (Indochina terrane). 3. Marginifera sp. 3.5 Measurement (mm.) Order PRODUCTIDA Sarytcheva and Specimen Length Width Thickness Sokolskaya, 1959 SM2014-2-005 20.10 22.25 1.70 Suborder PRODUCTIDINA Waagen, 1883 SM2014-2-006 23.15 25.45 14.20 Superfamily PRODUCTOIDEA Gray, 1840 SM2014-2-007 19.20 21.55 11.10 Family PRODUCTELLIDAE Schuchert, 1929 SM2014-2-008 17.45 25.35 8.10 Subfamily MARGINIFERINAE Stehli, 1954 SM2014-2-009 14.90 24.10 6.25 Genus Marginifera Waagen, 1884 Marginifera sp. SM2014-2-010 16.20 28.10 - Figure 3C SM2014-2-011 12.45 16.40 - 3.1 Examined specimens Four well preserved external indeterminate 4. Reticulatia sp.A valves and three external pedicle valves. Registered Order PRODUCTIDA Sarytcheva and specimen in SM2014-2-005 to SM2014-2-011 Sokolskaya, 1959 3.2 Diagnosis Suborder PRODUCTIDINA Waagen, 1883 See Grant, 19762 page 106 and Thonnarat Superfamily PRODUCTOIDEA Gray, 1840 et al., 201216 page 45 Family PRODUCTIDAE Gray, 1840 3.3 Description Subfamily DICTYOCLOSTINAE Stehli, 1954 Small-size shells are about 2.5 cm. wide; Genus Reticulatia Muir-Wood and Cooper, Triangular droplike shell outline; beak prominent anderect; 1960 the ventral valve is not clear sulcus; the greatest width is Reticulatia sp.A mid-length; shell ornamented by strong plicae and sparse Figure 3D short strong spines, spines normally broken. Internal structure cannot be observed. 406 Juanngam et al. J Sci Technol MSU

4.1 Examined specimens width; sub-trigonal shell outline; Pedicle valve is strongly One external both of pedicle and brachial convex with a slight beak; beak prominent rather straight; valves and ten external pedicle valves. Registered speci- cardinal extremities quite round to triangular; the costae, mens SM2014-2-012 to SM2014-2-023 about 10 – 12 costae in 1 cm. on surface; strong rugae 4.2 Diagnosis found rarely on front to mid-length; sulcus and costae are See Brunton et al., 200012 page 496 weakly developed to very clear. Internal structure cannot 4.3 Description be observed. Small to medium - size shells are about 5.4 Discussion 1.4 – 3.5 cm.; transversely subquadrate with hinge line Our Reticulatia sp is always characterized making greatest width; sub-trigonal shell outline; Pedicle by a distinct sulcus and bilobate character of lateral valve have strongly convex with slightly beak; beak promi- side which originates near umbo, and a remarkable nent rather straight; cardinal extremities quite round to ventral valve convex with deep median sulcus. The trianglular; the costae, about 10 – 12 costae in 1 cm., on R. sp. A specimens are difference from R. sp.B by well- surface; strong rugae found rarely on front to mid-length. developed to clear sulcus and costae which in R. sp.A Internal structure cannot be observed. cannot be observed. These specimens are similar to 4.4 Measurement (mm.) Reticulatia aff. R. huecoensis, Yanagida15 (1975, p. 26, pl. Specimen Length Width Thickness II, fi gs 16 – 19; pl. III, Figs. 1 - 2) from Huai Luang, Loei 17 SM2014-2-012 17.55 20.05 9.10 and Reticulatia uralica, Yanagida (1966, p. 54, pl. XVI, fi gs 7 - 8; pl. XVII, Figs. 1 - 4) and Reticulatia moelleri, SM2014-2-013 8.75 9.70 - Yanagida17 (1966, p. 56, pl. XXIII, fi gs 2 - 7) from North SM2014-2-014 11.30 11.20 - – Central Thailand (all Indochina Terrane) in general SM2014-2-015 20.05 29.65 15.70 outline, size and ornamentation. SM2014-2-016 27.70 19.70 - 5.5 Measurement (mm.) SM2014-2-017 16.55 23.20 - Specimen Length Width Thickness SM2014-2-018 16.75 21.40 10.80 SM2014-2-024 15.80 22.75 12.30 SM2014-2-019 8.10 11.40 5.60 SM2014-2-025 14.35 22.00 9.95 SM2014-2-020 13.35 22.20 11.35 SM2014-2-026 12.70 20.70 9.40 SM2014-2-021 15.45 23.30 6.45 SM2014-2-027 14.50 18.60 7.75 SM2014-2-022 15.40 20.90 - SM2014-2-028 11.60 14.10 6.35 SM2014-2-029 8.55 11.45 - 5. Reticulatia sp.B SM2014-2-030 14.80 14.35 8.55 Figure 3E SM2014-2-031 11.35 15.75 9.65 5.1 Examined specimens Two external both of pedicle and brachial valves SM2014-2-032 12.20 19.40 - and thirty-three external pedicle valves. Registered speci- SM2014-2-033 20.70 26.00 14.60 mens SM2014-2-024 to SM2014-2-059 SM2014-2-034 15.10 19.25 - 5.2 Diagnosis SM2014-2-035 19.80 22.35 11.90 12 See Brunton et al., 2000 page 496 SM2014-2-036 11.35 15.45 - 5.3 Description SM2014-2-037 8.70 21.40 - Small-size shells are about 1.4 – 3.5 cm.; SM2014-2-038 - 19.35 - transversely subquadrate with hinge line making greatest SM2014-2-039 - 45.50 32.65 Vol 33. No 4, July-August 2014 A new locality of well-preserved silicifi ed Early Permian brachiopods in Loei province, 407 NE Thailand

5.5 Measurement (mm.) cont. 6.3 Description Specimen Length Width Thickness Small-size shells are about 0.5 cm. wide; SM2014-2-040 8.90 11.30 4.30 weakly convex, more convex transversely than longitu- dinally with largest convexity at mid-length; shell outline SM2014-2-041 14.40 19.70 6.95 elongate sub-round trigonal; hinge line is short; surface SM2014-2-042 13.00 20.80 9.05 ornamented by costellae. Internal structure cannot be SM2014-2-043 12.45 19.95 9.65 observed. SM2014-2-044 16.75 21.1 14.65 6.4 Discussion SM2014-2-045 16.00 21.30 11.65 This specimen resembles Rhipidomella cf. R. SM2014-2-046 12.40 16.10 10.9 pecosi, Yanagida15 (1975, p. 18, pl. II, fi gs 5) from Huai 2 SM2014-2-047 14.05 15.45 10.10 Luang, Loei, Rhipidomella cordialis, Grant (1976, p37, pl.2, fi gs. 31 – 41; pl.3, fi gs. 1 – 53 ) from Ko Muk, Trang, SM2014-2-048 10.10 20.70 6.50 Rhipidomella cf cordialis, Thonnarat, et al.16 (2012, p. SM2014-2-049 20.20 21.00 18.40 35, pl. 2, fi gs. A - F) from Ban Ao Nam, Krabi in general SM2014-2-050 9.00 13.50 - outline but differs in the sulcus and shell surface of the SM2014-2-051 18.45 20.05 13.20 ventral and dorsal valves. In the Huai Luang specimens SM2014-2-052 16.10 22.70 16.25 the shell surface is fi nely costellate with a clear sulcus SM2014-2-053 16.10 22.70 16.25 whereas the Ko Muk specimens the shell surface is SM2014-2-054 16.30 19.40 - minutely roughened by a combination of fi ne growth lines and; and in the Ao Nam specimens the shell surface is SM2014-2-055 12.35 17.95 7.40 minutely smooth while our specimen has coarse costellae SM2014-2-056 16.90 19.25 - and no sulcus. SM2014-2-057 11.25 19.00 - 6.5 Measurement (mm.) SM2014-2-058 - 19.50 14.90 Specimen Length Width Thickness SM2014-2-059 54.90 54.55 32.10 SM2014-2-059 4.25 4.30 -

6. Rhipidomella sp. 7. SPIRIFERIDA fam. Indet. Order ORTHIDA Schuchert and Cooper, 1932 Order SPIRIFERIDA Waagen, 1883 Suborder DALMANELLIDINA Moore, 1952 Figure 3G Superfamily DALMANELLOIDEA Schuchert, 1913 7.1 Examined specimen Family RHIPIDOMELLIDAE Schuchert, 1913 Not well preserved three external pedicle Subfamily RHIPIDOMELLINAE Schuchert, 1913 valves. Registered specimens in SM2014-2-060 to Genus Rhipidomella Oehlert, 1890 SM2014-2-062. Rhipidomella sp. 7.2 Diagnosis Figure 3F See in Carter et al., 200614 page 1689 6.1 Examined specimen 7.3 Description One incomplete external pedicle valves. Small-size shells are about 2 cm. wide; oval Registered specimen SM2014-2-059. shell outline with exceeds length; cardinal extremities 6.2 Diagnosis quite sub-round; sulcus is slightly to not deep; shell orna- 2 See in Grant, 1976 page 37 ment is not clear. Internal structure cannot be observed. 408 Juanngam et al. J Sci Technol MSU

7.4 Measurement (mm.) 8.5 Measurement (mm.) Specimen Length Width Thickness Specimen Length Width Thickness SM2014-2-060 6.70 14.10 - SM2014-2-063 8.80 8.00 - SM2014-2-061 8.65 15.70 6.25 SM2014-2-064 31.30 36.45 8.45 SM2014-2-062 11.10 18.15 8.20 SM2014-2-065 8.35 17.05 1.45

8. Phricodothyris sp. Discussion Order SPIRIFERIDA Waagen, 1883 The main groups of silicified brachiopods obtained Suborder SPIRIFERIDINA Waagen, 1883 from shale in the Pha Dam section include cf. Reticulatia, Superfamily RETICULARIIDAE Waagen, 13 Marginifera, Phricodothyris, STROPHOMENIDA fam. Family ELYTHIDAE Fredericks, 1924 indet., SPIRIFERIDA fam. indet., Chonetinella and Subfamily PHRICODOTHYRIDINAE Caster, 1939 Rhipidomela and are illustrated respectively by number, Genus Phricodothyris George, 1932 in figure 2. Most of these specimens are small in Phricodothyris sp. size and with nearly complete valves. The faunais Figure 3H dominated by Reticulatia which constitute 76% of the 8.1 Examined specimen total. This we can designate a Reticulatia assemblage Quite not well preserved three valves; one of Marginifera indicates an Early Permian age which external pedicle valve, one of brachial valve; and one of supports the previous work of DMR8. The Reticulatia both of pedicle and brachial valve. Registered specimens assemblage sediments, are interpreted as having been SM2014-2-063 to SM2014-2-065. deposited in shallow marine conditions, Brachiopods 8.2 Diagnosis assemblage are generally sessile low-level epifaunal See Carter et al., 200614 page 1866 suspension feeders. A low energy environment is 8.3 Description indicated. More taxonomic and biostratigraphic work is Small to medium size shells are about 1 – necessary in order to fully appreciate the palaeogeo- 4.5 cm. wide; sub-round trigonal shell outline; wider than graphic, biogeographic and tectonic signifi cance of this high; cardinal extremities round and hinge line shorter newly discovered fauna. than greatest width; beak prominent and strongly in- curved; interarea not clear; sulcus absent except 1 sample Acknowledgments show narrow sulcus; maximum width close to midlength; It is my pleasure to thank Dr. Suree Teerarungsigul shell ornamented by rugae; faint growth lines. Internal (former director of Sirindhorn Museum) for her support structure cannot be observed. and encouragement, Miss Wilailuck Naksri, Miss 8.4 Discussion Kamonlak Wong-Ko and Dr. Clive Burrett are thanked The Phricodothyris is always characterized for their help in bringing this paper to completion and for by shell outline and by the remarkable character of the their advice. Grateful appreciation is due to the staff of ornamentation. These specimens are similar to Phrico- Sirindhorn Museum (Department of Mineral Resources) dothyris echinata, Yanagida15 (1975, p. 20, pl. 2, fi gs and Palaeontological Research and Education Centre 8 – 9) from Huai Luang, Loei, Upper Carboniferous and (Mahasarakham University) for their encouragement. Phricodothyris sp., Waterhouse, et al.,3 (1981, p. 65, pl. 2, fi gs. 18 – 19, pl. 3, fi gs. 1 – 18) from Ko Yao Noi, Krabi, Lower Permian but our specimen have stronger growth lines and differ from mode of costae. Vol 33. No 4, July-August 2014 A new locality of well-preserved silicifi ed Early Permian brachiopods in Loei province, 409 NE Thailand

References 11. Cocks, LRM, Jia-Yu, Rong. Strophomenida in Trea- 1. Shi, GR, Archbold, NW. Permian brachiopod faunal tise on Invertebrate Paleontology Part H Brachiopoda sequence of the Shan-Thai terrane: biostratigraphy, Revised Volume 2, 1st ed., USA.: The University of palaeobiogeographical afﬁ nities and plate tectonic/ Kansas Press 2000; 216 - 349. palaeoclimatic implications. Journal o/Southeast 12. Brunton, CHC et al. Productida in Treatise on In- Asian Earth Sciences 1995; 11(3): 177- 187. vertebrate Paleontology Part H Brachiopoda Revised 2. Grant, RE. Permian Brachiopods from southern Volume 2 - 3, 1st ed., USA.: The University of Kan- Thailand, Journal of Paleontology, V. 50 (supplement sas Pres 2000; 350 - 642. to no.3), Paleontological Society Memoir 9, 1976; 13. Williams, A, Harper, D.A.T. Orthida in Treatise on 269 p., 71 pl. Invertebrate Paleontology Part H Brachiopoda Re- 3. Waterhouse, JB, Pitakpaivan, K, Mantajit, N. The vised Volume 3, 1st ed., USA.: The University of Permian stratigraphy and paleontology of southern Kansas Press 2000; 714 - 846. Thailand. Thailand Geological Survey Memoir 4, 14. Carter, JL et al. Spiriferida in Treatise on Invertebrate 1981; 1–213. Paleontology Part H Brachiopoda Revised Volume 4. Shi, GR, Archbold, NW. Permian marine biogeo 5, 1st ed., USA.: The University of Kansas Press graphy of SE Asia Biogeograhy and Geographical 2006; 1689 - 1876. Evolution of SE Asia 1998; 57 – 72. 15. Yanagida, J. Upper Carboniferous Brachiopods from 5. Yanagida, J. Permian brachiopods from central Wang Sapung, North Thailand. Contributions to Ko- Thailand, Geology and Palaeontology of Southeast bayashi, Teiichi. and Toriyama, Ryuzo Geology and Asia., V.1, 1964; 143 – 165. Palaeontology of Southeast Asia Volume 16, Tokyo: 6. Yanagida, J, Nakornsri, N. Permian brachiopods University of Tokyo Press 1975; 1 – 31. from the Khao Hin Kling Area near Petchabun, North- 16. Thonnarat, D, et al., Brachiopod site of the Ao Nam central Thailand, Bulletin of the Kitakyushu Museum Area, Laem Sak Subdistrict, Ao Luek District, Krabi of Natural History., V.20, 1999; 105 – 136, pls. Province, Southern Thailand. Technical Report No. 26 – 32. BFP.3/2012., Bangkok: Bureau of Fossil Protection, 7. Pérez-Huerta, A., et al., Permian Brachiopods from Department of Mineral Resources 2012; 96 p., 23 new localities in northeast Thailand: Implications for pl. paleobiogeographic analysis. Journal of Asian Earth 17. Yanagida, J. Early Permian brachiopods from north- Sciences 30., 2007; 504 – 517. central Thailand. Geology and Palaeontology of 8. Department of Mineral Resources. The classiﬁ cation Southeast Asia 3, 1966; 46–97. of Mineral and Geology Resources for Management, Loei. Province, Thailand. Bangkok. 2008; 107 p. 9. Chairangsee, C., et al., Geology of the Ban Sup Quadrangle, Geological Survey Report No.0071., Department of Mineral Resources 1987; 35 p. 10. Williams, A, Rowell, AJ. Morphological terms applied to brachiopods in Treatise on Invertebrate Paleonto logy Part H Brachiopoda Volume 1, 1st ed., USA.: The University of Kansas Press 1965; H139 - H154. 410 Juanngam et al. J Sci Technol MSU

Pha Dam Section

Figure 1 Map of site (Pha Dam Section) from where the fossils were collected.

Figure 2 Distribution pattern of brachiopods diversity from the Pha Dam Section. Vol 33. No 4, July-August 2014 A new locality of well-preserved siliciﬁ ed Early Permian brachiopods in Loei province, 411 NE Thailand

A B

E F

G H

Figure 3 A: ventral view of STROPHOMENIDA fam. Indet., B: ventral view of cf. Chonetinella sp., C: ventral view of cf. Marginifera sp., D: ventral view of cf. Reticulatia sp.A, E: anterior view of cf. Reticulatia sp.B, F: ventral view of cf. Rhipidomella sp., G: ventral view of SPIRIFERIDA fam. Indet., H: ventral view of cf. Phricodothyris sp. , scale bar equal 1 cm.